- Direct immunofluorescence (DIF) microscopy and indirect immunofluorescence (IIF) salt-split skin (SSS) test are both good diagnostic tools for pemphigoid, with very high diagnostic performance from a combined test.
Why this matters
- Minimal diagnostic criteria for pemphigoid have not previously been established.
- 343 of 1125 subjects (30.5%) received a pemphigoid diagnosis.
- 21.6% of those presented with nonbullous pemphigoid.
- DIF microscopy had 88.3% (95% CI, 84.5%-91.3%) sensitivity and 99.2% (95% CI, 98.3%-99.7%) specificity for pemphigoid diagnosis.
- IIF SSS had 77.0% (95% CI, 72.2%-81.1%) sensitivity (P<.001 vs dif microscopy and ci specificity for pemphigoid diagnosis.>
- Combined DIF microscopy and IIF SSS had 98.8% (95% CI, 97.0%-99.7%) sensitivity and 99.1% (95% CI, 98.2%-99.6%) specificity for pemphigoid diagnosis.
- Presence of skin blisters was the best predictive factor for pemphigoid diagnosis (OR, 7.7; 95% CI, 5.7-10.5), while pruritus was not significantly associated (OR, 0.6; 95% CI, 0.3-1.2).
- 1125 patients with suspected pemphigoid who received a biopsy DIF test and an IIF on SSS substrate test as well as 1 or more routine immunoserologic tests were analyzed to compare diagnostic accuracy.
- Funding: None disclosed.
- Single-center, retrospective study.